//
//  AudioWrapper.m
//  newshaohuo
//
//  Created by shaohuo on 2018/3/14.
//  Copyright © 2018年 shaohuo. All rights reserved.
//

#import "AudioWrapper.h"
#import "lame/lame.h"

@implementation AudioWrapper

+ (void)audio_PCMtoMP3:(NSString *)soucePath andDesPath:(NSString *)desPath {
    NSLog(@"开始转换");
    
    @try {
        int read, write;
        
        FILE *pcm = fopen([soucePath cStringUsingEncoding:1],
                          "rb"); // source 被转换的音频文件位置
        fseek(pcm, 4 * 1024, SEEK_CUR); // skip file header
        FILE *mp3 = fopen([desPath cStringUsingEncoding:1],
                          "wb"); // output 输出生成的Mp3文件位置
        
        const int PCM_SIZE = 8192;
        const int MP3_SIZE = 8192;
        short int pcm_buffer[PCM_SIZE * 2];
        unsigned char mp3_buffer[MP3_SIZE];
        
        lame_t lame = lame_init();
        lame_set_in_samplerate(lame, 44100.0);
        lame_set_VBR(lame, vbr_default);
        lame_init_params(lame);
        
        do {
            read = fread(pcm_buffer, 2 * sizeof(short int), PCM_SIZE, pcm);
            if (read == 0)
                write = lame_encode_flush(lame, mp3_buffer, MP3_SIZE);
            else
                write = lame_encode_buffer_interleaved(lame, pcm_buffer, read,
                                                       mp3_buffer, MP3_SIZE);
            
            fwrite(mp3_buffer, write, 1, mp3);
            
        } while (read != 0);
        
        lame_close(lame);
        fclose(mp3);
        fclose(pcm);
    } @catch (NSException *exception) {
        NSLog(@"%@", [exception description]);
    } @finally {
        NSLog(@"MP3生成成功");
    }
}

@end
